Preparation of metal chelates of beta-iminocarbonyls



United States Patent @flice 3,373,377 Patented Mar. 12, 1968 3,373,177PREPARATTON F METAL CHELATES 0F fi-IMINOCARBONYLS Donald C. Young,Fullerton, Calif., assignor to Union Oil Company of California, LosAngeles, Calif a corporation of California No Drawing. Filed May 20,1963, Ser. N 0. 231,757 3 Claims. (Cl. 260-429) This invention relatesto metal complexes of S-iminoketones and to a method for theirpreparation.

Specifically, this invention relates to the metal complexes of organicligands having the following structure:

it i R1OCH2UR:' which exist in tautomerism with the following:

wherein R and R are selected from the class consisting to hydrogen,e.g., iminoaldehydes and alkyl groups having from 1 to about 5 carbonssuch as methyl, ethyl, isopropyl, propyl, butyl, isobutyl amyl, isoamyl,etc. Preferably both R and R are alkyl. The imino form is the activeform of the ligand and examples of suitable ligands are as follows:l-rnethyl 3-iminopropanone, l-ethyl 3-iminopropanone, l-isopropyl3-imin0propanone, 3-isopropyl 3-iminopropanone, 1,3-diisopropyl3-iminopropanone, l-propyl 3-iminopropanone, 3-propyl 3-iminopropanone,1,3-dipropy1 3-iminopropanone, 1-isobutyl S-iminopropanone, 3-butyl3-iminopropanone, 1,3- dibutyl 3-iminopropanone, l-amyl3-iminopropanone, 3-isoamyl 3-iminopropanone, 1,3-diisoamyl3-iminopropanone, etc.

In general, the aforementioned organic compounds function as bidentateand as tridentate ligands with many metal ions; the centers of metal ionattraction being the imino nitrogen, the carbonyl oxygen and theunsaturate bond. The resulting metal chelates are very stable since theexistence of an unsaturated bond in the chelate ring imparts a resonancestability to the chelate.

The ligands previously described, or rather, their tautomers can bereadily prepared from the corresponding diketenone by reacting thediketenone with ammonia in a nonaqueous reaction medium at temperaturesbetween about 0 and about 100 C. and sufiicient pressure to maintainliquid phase reaction conditions. The diketenone is, of course, indesmotropism with the enol form and this form reacts with ammonia. Thereaction proceeds in two stages; in the first reaction, the ammoniumsalt of the enol compound is formed which upon further heatingdecomposes to form the amino-ketenone compound and water. The organicphase, containing the desired product, is thereafter separated from theaqueous phase and then distilled to recover the product.

Preferably, ambient temperatures are employed in the first step for thepreparation of the ammonium salt of the enol form of the diketenone,e.g., temperatures between about 15 and about 65 C., most preferablybetween about 20 and about 50 C. and a pressure suflicient to maintainliquid conditions, generally between about atmospheric and aboutatmospheres, preferably between about atmospheric and about 5atmospheres. The ammonium enol salt is readily formed under theseconditions, generally within about 5 to about 30 minutes and,thereafter, the reaction medium is heated to a temperature between about50 and about 150 C., preferably between about 60 and about 80 C. toobtain the aminoketenone compound.

Because the aminoketenone will readily hydrolyze to the diketenone, itis important to promptly separate the organic phase from the aqueousphase formed during the latter heating step. After the phases have beenseparated, then the organic phase can be worked up in a conventionalmanner, e.g., fractionation to purify the aminoketenone compound of thenon-aqueous reaction medium.

Various organic solvents can be employed as the reaction mediurnincluding hydrocarbons such as toluene, xylene, benzene, hexane,heptane, octane, etc.; alkanols such as allyl alcohol, butyl alcohol,amyl alcohol, hexanol, heptanol, decanol, etc.; esters such as ethylpropionate, propyl acetate, butyl formate, butyl acetate, ethylbutyrate, amyl acetate, amyl butyrate, etc.; halogenated hydrocarbonssuch as dichloropropane, trichloroethane, chlorobenzene, bromobenzene,trichloropropane, pentachloroethane, dichlorobenzene, etc.; carboxylicacids such as acetic acid, butyric acid, pentanoic acid, toluic acid,terephthalic acid, isophthalic acid, trimellitic acid, etc.

The unsaturated beta-diketone compounds that are employed as thestarting materials in the aforedescribed reaction can, in mostinstances, be obtained commercially. The preparation of these materials,however, is relatively simple and comprises reacting an olefin with adiketene in the presence of a suitable acylation catalyst. This methodof preparation is described in US. Patent 2,453,- 619. As an example,about one mol of diketene and one mole of diisobutylene can be mixed andabout one-half mo]v of commercial percent sulfuric acid added dropwiseto the mixture while stirring and maintaining the temperature belowabout F. After allowing about an hour to complete the reaction, about500 ml. of water can be added to dissolve the catalyst. The organiclayer can then be separated from the aqueous layer and the diketonerecovered therefrom by a suitable procedure. Preferably the organiclayer is washed with water and treated with dilute sodium carbonate toremove traces of acid and then distilled under vacuum to obtain thediketone. The diketone is thereafter treated with ammonia in anon-aqueous medium in the manner previously described to obtain theiminoketone ligand employed to prepare the metal chelates of myinvention.

The metal complexes of the aminoalkenones that comprise my invention areprepared by reacting the ligand, i.e., ,B-irninoketone, with anammoniacal solution of the metal. In general, any metal that formsammine complexes in ammoniacal solutions will readily form a complexwith the ligand according to my invention.

The chemistry of metal ammine salts and their formation is a welldocumented field, i.e., see volume X of A Textbook of InorganicChemistry edited by J. Newton Friend (1928). In general, the transitionmetals that readily form stable a-mmine complexes in aqueous ammoniacalsolutions can be employed to form the complex with the ligand of myinvention. Generally, included are the following metals and their knownammino complexes: Copper: pentammino, tetrammino, diammino and monamminocupric halides, nitrates and sulfates;

Silver: triammino, sesquiammino, diammino and monammino silver halidesand nitrates;

Gold: dodecammino, triammino, diammino and monammino-aurous halides andnitrates;

Zinc: hexammino, tetrammino, diammino and monammino zinc halides,nitrates and sulfates;

Cadmium: hexammino, tetrammino, triammino, diammino and monamminocadmium halides, nitrates and sulfates;

Mercury: triammino-dimercuric, dodecammino, tetrammino, triammino,diammino and monammino mercuric halides;

Tin: diammino, monoammino and octammino stannic halides,diammino-stannous halides;

Lead: tetrammino, diammino and monammino lead halides;

Bismuth: triammino bismuth halides;

Chromium: hexammino, aquo-pentammino, diaquotetrammino,triaquo-triammino, tetraquodiammino, hydroxo-pentammino,hydroxoaquotetrammino, hydroxodiaquotriammino, hydroxotriaquo-diammino,acidopentammino, acidoaquotetrammino, dihydroxy-diaquodiammino, diacidotetrammino diacido-aquotriammino, diacido-diaquodiammino,triacido-triammino, trihydroxo-aquo-diammino chromium halides, nitratesand sulfates;

Molybdenum: monammino molybdenum and decammino dimolybdenum halides;

Manganese: ammino-manganous halides, nitrates and sulfates;

Iron: hexammino, pentammino, diammino and monammino ferrous halides andsulfates;

Cobalt: hexammino, hexahydroxyammino, aquopentammino, diaquo-tetrammino,triaquo-triammino, hy droxopentammino, hydroxo-aquo-tetrammino,acidopentammino, acido-aquo-tetrammino, acido-diaquo-triammino,acido-triaquo-diammino, hydroxo-acido-tetrammino, diacido tetrammino,diacido aquo triammino, diacido-diaquo-diammiuo cobaltic halides,nitrates and sulfates;

Nickel: diammino, triammino, tetrarnmino, hexammino and pentamminonickel halides, nitrates and sulfates.

Ruthenium: heptammino-diruthenium halides;

Rhodium: hexammino rhodium halides, nitrates;

Palladium: diammino tetrammino palladous halides;

Osmium: diarnmino, tetrammino osmium halides, nitrates and sulfates;

Iridium: diammino, tetrammino, hexammino, aquopentamrnino,acido-pentammino, hydroxy-pentammino, diacido-tetrammino,triacido-triammino iridium halides, nitrates, sulfates; and

Platinum: tetrammiho, acido-triarnmino, diacido-diamrnino,triacido-ammino platinous halides, nitrates and sulfates, hexarninino,acido pentammino, diacidotetrammino, tr'iacido-triammino,tetracido-diarnmino pentacido-ammino platinic halides, nitrates andsulfates.

The preceding listing does not exclusively list all useful metal amminecomplexes, but rather is set forth to illustrate representative metalsand their ammine complexes that can be used in my invention. Variousother metals, known to form ammine complexes, can also be used such asthose known to form ammine complexes in alkaline solutions from thelanthanum series, including cerium, praseodymium, neodymium, promethium,samariu'm, europium, gadolinium, terbium, dysprosium, holmiurn, erbium,thulium, ytterbium and eutetium, as well as from the actinium series,i.e., thorium, protactinium, uranium, neptunium, plutonium, americium,curium, berkelium, californium, einsteinium, ferminium and mendelviurn.

In general, the ammonia content of the aqueous ammoniacal solutionemployed to obtain the ammine complex can be between about 5 and about50 weight percent, preferably between about and about weight percent.Sufficient of the metal salt is added to obtain a concentration of themetal in the solution between about 1 and about 10 weight percent. Theseammoniacal solutions of the metal ammine complex can be prepared atambient or slightly elevated temperatures as desired to effect thesolubility. In general, temperatures between about 20 and about 100 C.at atmospheric or slightly elevated temperatures, up to about 10atmospheres, can be employed as desired. Preferably, the preparation ofthe solution is at ambient conditions, between about 20 and about C.

The complex of the metal ion and the iminoketone ligand can be obtainedsimply by dissolving the ligand in the aforedescribed ammoniacal metalammine salt solution. In general, ambient temperatures are also employedin this step, between about 5 and about 50 C.; between about 20 andabout 25 C. being preferred. Again, to prevent substantial loss ofammonia during this step, slightly elevated pressures can be maintainedwhen the mixing is performed at temperatures above about 25 C. or whenusing solutions with high ammonia contents to avoid loss of ammonia,e.g., pressures between about atmospheric and about 10 atmospheres.

The metal complex precipitates, in most instances, from the ammoniacalsolution as a crystalline solid and can be recovered therefrom byconventional solid-liquid separating techniques, e.g., by filtering,centrifuging, etc. To avoid the presence of two solids, it is preferredto add the ligand to the ammoniacal solution as an aqueous solution. Ininstances where the metal iminoketone complex is quite soluble in water,e.g., the cupric iminoketone complex, it can be precipitated therefromby the addition of an agent which lowers its solubility, e.g., acetone,acetic acid, etc. Also, if desired, the metal iminoketone complex can beprepared by admixing stoichiometric quantities of the metal amminecomplex and the iminoketone ligand and thereafter evaporating theaqueous solution. Preferably, however, the metal iminoketone complex issimply recovered as a solid precipitate from the ammoniacal solution.

If desired, other methods for the preparation of the metal complex canbe employed provided that the presence of water is excluded in theirpreparation. To illustrate, the metal complex can be obtained bydissolving a soluble salt of any of the aforedescri-bed metals in apolar organic solvent such as an alcohol, or carboxylic acid. Thus, analcoholic solution, e.g., methanol, ethanol, propanol, isopropanol,butanol, isobutanol, amvl alcohol, isoamyl alcohol, etc., can beemployed to dissolve a soluble salt such as a halide, chloride,fluoride, iodide, bromide, or sulfate, nitrate, acetate, of any of theaforedescribed metals. To the alcoholic solution is thereafter added thesolid organic ligand or an alcoholic solution of the ligand. Theaforedescribed metals can also be dis solved in carboxylic acids such asacetic, propionoic, butypri-c, pentanoic, toluic, etc. and reacted insuch solution with the organic ligand. As with the preparation in theammonical solution, the metal complexes separate as precipitates ineither the alcoholic or carboxylic acid reaction mediums. Thisprecipitate can be readily separated therefrom by conventionalsolid-liquid separation steps previously described.

The metal complexes of my invention can be employed for a variety ofuses as fungicides and pesticides, particularly with those metals havingknown toxic effect such as copper, mercury, beryllium, silver, etc. Thecomplexes can also be employed as catalyst for various reactions, e.g.,the titanium complex can be employed as a polymerization catalyst, thezirconium complex as a condensation catalyst, and, in particular, thenoble Group VIII metal complexes can be employed as hydrocarbonoxidation catalysts. Additionally, complexes of any of the followingmetals a'foredescribed can be employed as sources of minor nutrients foragricultural purposes:

For use as fungicides and pesticides, the metal complex can beformulated into a wettable powder by grinding together and intimatelyadmixing the following ing-redients:

Percent by weight This composition is dispersed in water with the aid ofa high speed blender to obtain a spray composition of the desiredconcentration.

Various metal complexes of my invention can also be used as catalystsfor particular reactions such as the oxidation of olefins to valuablecarbonyl compounds such as epoxides, aldehydes, ketones, unsaturatedesters, etc., by use of the noble metal complexes aforedescribed insubstantially anhydrous reaction mediums. To illustrate, ethylene can beoxidized to a high yield of carbonyls by reacting ethylene with oxygenat a temperature between about 100 and about 200 C. in a substantiallyanhydrous organic solution of the palladium complex. Similarly,propylene and butene can be oxidized to yield, respectively, acetone,propionaldehyde, methyl ethyl ketone and butyraldehyde. Slight amountsof epoxides can also be obtained in this oxidation.

My invention will now be illustrated by the following exemplifieddescriptions:

Example 1 To a two-liter flask was added 1000 grams toluene and 500grams of commercially obtained 2,4 pentane-dione. Anhydrous ammonia wasslowly added while stirring to maintain the temperature below about 50C. The flask contents were then permitted to cool to room temperature,transferred to a separatory funnel and an aqueous phase comprising 73grams of water Was removed. The organic phase was transferred to adistillation flask and distilled to recover about 400 grams of productboiling from 206 to 215 C. Subsequent distillation of the productpermitted recovery of the aminoketenone in pure state, atmosphericboiling points 209 C. The product is a deliquescent crystalline solidwith a melting point of about 42 C. It is soluble in polar solvents suchas water and acetone and aromatic solvents, but insoluble in normalparaflins.

Example 2 Metal amine complexes were prepared by dissolving thefollowing salts in an aqua ammonia of percent strength ammonia:

Nickel chloride, cupric chloride, cobaltous chloride, cerous chlorideand palladium chloride.

To each of the ammoniacal solutions of the metal ammine salts was addeda portion of the crystalline solid prepared in Example 1. The mixtureswere warmed gradually until a color change was observed. The nickeliminoketonecomplex was formed and separated as a water insolublered-orange solid. The copper iminoketone complex formed as a blue-graywater insoluble solid and the cobalt iminoketone complex formed as awater insoluble red solid. The cerous iminoketone formed as a waterinsoluble gray to lavender colored solid and the palladium iminok-etonecomplex formed as a water insoluble yellow solid.

The preceding examples are intended only to illustrate the mode ofpracticing my invention and are not intended to be unduly limitingthereof. It is apparent from the preceding discussion that the method offorming stable complexes of metal ions and fl-iminoketones can bereadily applied to all metals that form stable ammine salts inammoniacal solutions as this condition of the metal ion is generallyrequired in preparation of the complex in aqueous media.

I claim:

1. The preparation of a metal chelate salt from a transition metal thatforms ammine salts in aqueous ammoniacal solutions and a ligand havingthe following structure:

0 N H I; R\C-CH2 -R2 wherein R and R are selected from the classconsisting of hydrogen and alkyl groups having 1 to about 5 carbons;said method comprising forming the ammine salt of said metal in anaqueous ammoniacal solution and thereafter admixing said ligand Withsaid solution containing from about 5 to percent ammonia at atemperature between about 5 and about 50 C. to form said complex as asolid precipitate.

2. The preparation of claim 1 wherein R and R are each alkyl and have 1to about 3 carbons.

3. The preparation of claim 2 wherein said ligand is 1,3-dimethyl3-iminopropanone.

References Cited UNITED STATES PATENTS 3/ 1949 Swiss. 4/ 1942 Peski eta1.

TOBIAS E. LEVOW, Primary Examiner. H. M. S. SNEED, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION March 12, 1968Patent No 3,373 177 Donald C. Young It is certified that error appearsin the above identified patent and that said Letters Patent are herebycorrected as shown below:

Column 6, line 28, after "solution" insert containing from about 5 to 50percent ammonia lines 29 and 30 1 strike out "containing from about 5 to50 percent ammonia".

Signed and sealed this 24th day of June 1969.

(SEAL) Attest:

Edward M. Fletcher, Jr.

Attesting Officer Commissioner of Patents WILLIAM E. SCHUYLER, JR.

1. THE PREPARATION OF A METAL CHELATE SALT FROM A TRANSITION METAL THATFORMS AMMINE SALTS IN AQUEOUS AMMONIACAL SOLUTIONS AND A LIGAND HAVINGTHE FOLLOWING STRUCTURE: